Lake Utonai (ウトナイ湖, Utonai-ko) is a shallow freshwater lake in Tomakomai, Iburi Subprefecture, Hokkaidō, Japan. It is within the Lake Utonai Sanctuary, created in 1981 as the first bird sanctuary designated in Japan. It later became the fourth Ramsar site in Japan in 1989.
Other names include Kim-un-to, Kimke-to, Utnay-to, Utnay-tō, Utonai-numa, and Utsunai-numa.
Etymology and history
There are multiple original Ainu names for Lake Utonai, including キムント (kim-un-to), meaning "a wetland with a mountain", and キムケト (kimke-to), meaning "wetland deep in the mountains".[2] Other names and variations include ウッナイト (utnay-to), meaning "rib river wetland" or "where small streams come together" and ウトナイトー (utnay-tō).[2][3] Utonai-numa (ウトナイ沼) and Utsunai-numa (宇都内沼) are also used.[4][5][6]
Lake Utonai was the first designated bird sanctuary in Japan, through the efforts of the Wild Bird Society of Japan and the city of Tomakomai in 1981.[3][7] The lake and the surrounding area was designated a Ramsar site in Japan in July 1989,[1][8] the fourth such designation in Japan.[7] It is designated a Special Protection Area of a National Wildlife Protection Area.[7][8]
Geography
Lake Utonai is a small lake, with an area of 2.20 square kilometres (0.85 sq mi), an average depth of 0.6 metres (2.0 ft), and a maximum depth of 1.5 metres (4.9 ft). The shorelines is approximately 9.5 kilometres (5.9 mi) long.[3] Around the lake is a wide area of swampywetland dotted with small ponds and bogs, all part of the Bibi River floodplain.[3][8] The Yūfutsu River, which is part of the Abira River drainage system, flows into the lake through the eastern part of Tomakomai and also drains the lake. The Bibi, Otarumappu, and Tokisatamappu rivers also empty into the lake.[9]
The creation of the Lake Utonai Sanctuary began in May 1976 as an effort to protect habitat for the Okinawa woodpecker.[4] In November that same year, a foundation was established to work toward that goal, collecting over ¥100 million.[4][7] In May 1979, Lake Utonai was selected as the location for the first bird sanctuary for the foundation in order to protect it from increased development in the area.[7] The groundbreaking for the nature center was held in February 1980, and volunteer camps were held in August 1980 and March 1981. The nature center officially opened on 10 May 1981.[4]
The sanctuary protects 510 hectares (2.0 sq mi), including Lake Utonai and much of the surrounding area. This area is the only remaining wetland area on the Yūfutsu flood plain.[7]
^ abcd"Utonai-ko". Ramsar Sites Information Service. Archived from the original on 16 February 2020. Retrieved 25 March 2021.
^ abアイヌ語地名リスト、P11-20 [Ainu Place Name List, pages 11-20] (PDF) (in Japanese). Office of Ainu Measures Promotion. 4 April 2018. p. 16. Archived(PDF) from the original on 10 February 2021. Retrieved 26 March 2021.